The present invention relates to seals for the reduction of leakage between turbine components and more specifically to seal slots in nozzle segments having complex profiles and an additive manufacturing process for making such seal slots.
Gas turbine engine components such as turbine nozzles are often configured as a ring of side-by-side segments. It is known that leakage at the gap between adjacent segments leads to inefficiencies in aircraft engines. Conventional ways to reduce this leakage include installation of sealing slots and splines positioned such that leakage pathways between the segments are blocked or impeded. In this regard, each segment has an edge having a spline slot formed therein. Adjacent spline slots of two adjacent segments are configured to receive opposite sides of the same spline. In this manner, leakage pathways along the gap between two adjacent segments are reduced by cooperatively engaged splines and spline slots.
Conventional spline slots are configured to receive a spline and in this regard are often configured as generally U-shaped channels. Some conventional spline slots have parallel sides that are spaced-apart a predetermined width. Corresponding splines are configured such that they are narrower than this width such that the spline can be received within the spline slot.
One problem with conventional spline slots and splines is that leakage occurs through pathways defined between the substantially parallel spline and adjacent wall of the spline slot.
Another problem with conventional spline slots and methods for forming them is that the ability to leave a blind access region behind additional features cannot be accommodated by casting, and would require extreme measures to machine thereby leading to highly variable results.
Another problem with conventional spline slots and spline configurations is that the spline can be removed from a spline slot inadvertently.